CROP DEVELOPMENT UNDER IRRIGATION 163 



seeding. If irrigation is applied very early to such lands, 

 the root-system is likely to be retarded in its growth, and 

 the final crop-yield may be greatly reduced. On soils 

 practically saturated, at planting time, from the winter 

 rains and snows, the first irrigation should be postponed 

 as long as possible so that a strong root-system can be 

 developed to use fully the water applied plentifully later 

 in the season. This doctrine has been confirmed by many 

 experiments under true irrigated conditions. For instance, 

 in districts where the winter precipitation is so high (say 

 8 inches during the six months of fall and winter) that 

 the soil to a depth of 10 to 12 feet is approximately 

 saturated, no benefits result from irrigation immediately 

 after sowing; and the effect of the first irrigation becomes 

 greater as it is removed in time from the date of seeding. 



Naturally, however, where the climatic conditions are 

 such that at seeding time the soil is not well filled with 

 water, thorough irrigation immediately before or after 

 planting would do much to insure a proper germination 

 of the seeds and a more rapid development of the root- 

 system. Even when this is done, the longer the first 

 irrigation is postponed, the better it will be for the crop, 

 which then can better develop its root-system. Let it 

 not be forgotten by the irrigation farmer that, in a rela- 

 tively dry soil, roots will develop faster and will go more 

 vigorously in search of water and food. 



107. Proportion of leaves and stems. The part of 

 the plant above ground is also definitely affected by 

 the quantity of water applied. As the water applied to the 

 soil increases, the whole plant becomes longer. This is 

 true with all the common crops, such as wheat, oats, 

 barley, rye, beans and buckwheat. Every farmer has 

 observed that in fields to which water is added abundantly 



